I didn't quite get it myself maybe partly cause english isn't my native language and the profanity was distracting but I think the general idea was about art being put on a leash with rules and manufactured for the consumer (like in the scene where the teacher CORRECTS the art of children instead of leaving it as it is) rather than being created as it is.It also seems to be about being too obsessed with glorifying old art and not really creating anything unique to our current time.
Review of Manifesto
